IR Spectroscopy as a Promising Diagnostic Tool for Cancer Screening

Infrared (IR) spectroscopy is gaining traction as a powerful tool for the rapid diagnosis of various diseases, particularly cancer. Research conducted by Shaiju S. Nazeer, Ravi Kumar Venkataraman, Ramapurath S. Jayasree, and their colleagues at the Sree Chitra Tirunal Institute for Medical Sciences and Technology in India have examined the utility of IR spectroscopy in analyzing serum and plasma samples as liquid biopsies (1). Their findings, published in the journal Analytical Chemistry, reveal the promising potential of this method while underscoring critical challenges that must be addressed before it can be widely implemented in clinical settings (1).

Spectroscopic Methodology
The fundamental principle of IR spectroscopy lies in its ability to capture the molecular fingerprint of clinical samples based on the vibrational modes of chemical bonds. The technique utilizes the variations in spectroscopic signatures resulting from molecular vibrations of lipids, proteins, nucleic acids, and carbohydrates (1-3). In particular, the researchers focused on spectral analysis in the 1500–1700 cm⁻¹ region, where protein amide I and II bands are prominent.

Various analytical methods, including univariate approaches such as ratiometric analysis and secondary protein structure analysis, were employed to evaluate cancer-associated molecular alterations. Multivariate analyses, including principal component analysis (PCA) and support vector machine (SVM) modeling, have also been utilized to enhance diagnostic accuracy by distinguishing between healthy controls and various cancer stages (1).

Read More: FT-IR Spectroscopy

Challenges in Clinical Translation
Despite the remarkable capabilities of IR spectroscopy, its routine adoption in clinical diagnostics remains limited due to several confounding factors. The authors emphasized that blood sample analysis can be complicated by issues such as hemolysis, dietary influences, and variations in individual health conditions. Notably, the quality of spectral data can be adversely affected by the coffee ring effect (CRE), a phenomenon that leads to nonuniform distribution of analytes during the drying process of serum or plasma samples (1-3).

The researchers highlighted that nearly 90% of serum/plasma consists of water, which interferes with the IR spectral analysis by overshadowing critical spectral signals in the 1500–1700 cm⁻¹ region. The remaining components, including proteins, creatinine, and amino acids, contribute to the spectral signatures relevant for disease diagnosis. As such, a robust methodology that mitigates the effects of water interference and the CRE is essential for accurate spectral evaluation (1).

Proposed Solutions and Standard Operating Procedures
To overcome these challenges, the study outlines a series of precautionary measures. Researchers recommend employing modifications to IR-reflecting surfaces and utilizing solvent-assisted drying methods to eliminate the CRE. Additionally, the importance of maintaining consistent dietary patterns and limiting alcohol consumption among participants in clinical trials is emphasized to ensure the reliability of spectral data (1).

The authors propose a structured workflow for conducting IR spectroscopy-based diagnostics that incorporates the consideration of health histories, including cardiovascular and hepatic conditions. They stress the need for appropriate numerical methods to enhance the sensitivity and specificity of diagnostic results based on the quality of the spectral data set (1).

The research indicates that while IR spectroscopy offers a noninvasive alternative for cancer diagnosis using blood derivatives, the pathway to clinical implementation is fraught with challenges. Addressing confounding factors through rigorous standard operating procedures will be vital for advancing this promising diagnostic tool. As the field progresses, the integration of these methodologies into clinical practice could pave the way for more accessible and efficient cancer screening methods (1-3).

References

(1) Nazeer, S. S.; Venkataraman, R. K.; Jayasree, R. S.; Bayry, J. Infrared Spectroscopy for Rapid Triage of Cancer Using Blood Derivatives: A Reality Check. Anal. Chem. 2024, 96, (3), 957–965. DOI: 10.1021/acs.analchem.3c02590

(2) Andrei, A. B.; Fleschin, Ş.; Aboul-Enein, H.Y. Cancer diagnosis by FT-IR Spectrophotometry. Rev. Roum. Chim. 2015, 60 (5-6), 415–426. PDF Copy at: https://www.researchgate.net/profile/Andrei_A_Bunaciu/publication/284737589_Cancer_diagnosis_by_ft-Ir_Spectrophotometry/links/566aac0e08ae430ab4f81e89.pdf (accessed 2024-10-28).

(3) Bunaciu, A. A.; Hoang, V. D.; Aboul-Enein, H. Y. Applications of FT-IR Spectrophotometry in Cancer Diagnostics. Crit. Rev. Anal. Chem. 2015, 45 (2), 156–165. DOI: 10.1080/10408347.2014.904733